The % chance on the dungeons means you should be able to see what is clearable with your current team.
You start with 9 Delvers in backwater,
This enables 2 teams that can delve from day one.
Send the 2nd party into a dungeon to get some XP and gain some coin for the coffers,
There's also quests from day 2 in the tavern that can pay as well and let you send a solo delver
Key is to not over extend too early with outgoing costs until your stable,